The episode opens with a TV promo for the upcoming Wallace Cup as Dawn brushes her Pokemon while watching the promo. As she gets excited, she notices Ash training outside for his upcoming Gym Battle with the Pastoria City Gym Leader. As Dawn get's ready to go outside, she overhears on the TV that the Wallace Cup is going to be taking place at Valor Lakefront in a few days. Dawn comes outside, but stops at a distance as she has thoughts about Ash go through her head. This seems to get her all fired up as she gathers all of her Pokemon, including Buneary who had been with Ash and the others looking on. After a little pep talk, Dawn decides to work on her Pokemon's combinations. She has Piplup use Whirlpool, Buneary use Bounce, Ambipom use Swift, and Pachirisu use Discharge. Soon Dawn realizes she got carried away and frantically runs telling her Pokemon to stop their attacks, but she only ends up getting blasted by all of their attacks at once. Ash, Brock, and all their Pokemon rush over to check on Dawn and ask if she's okay. As usual, Dawn tells them there's no need to worry. Once, she regains some sort of composure, Dawn says that she was trying to do something different, but then remembered what Zoey said and realized she was doing it all wrong. Ash and Brock try to cheer Dawn up, but before that pep talk gets finished, a "Sinnoh Now" newscrew walks by and asks them if they've seen Wallace. This gets Dawn's attention and she jumps up while Ash is standing there clueless as he has no clue who Wallace is. After Ash gets his Wallace lesson for the day, the reporter, Rhonda, says that she's heard Wallace is somewhere around Lake Valor, but his staff has declined to comment on his exact whereabouts. Dawn and the gang decide to look for Wallace themselves once Rhonda leaves.
Later, Ash and co. are wandering where to look for someone famous. Pikachu and Piplup then sense something to their right so Dawn and the others decide to check it out. They soon come up on a Milotic which appears to be singing. After looking it up on her dex, Dawn notices the sillouhete of Wallace to their right as Wallace and Milotic notice them. After some introductions, everyone decides to relax as Pikachu and Piplup go have some fun with Milotic. Wallace describes his time since arriving in Sinnoh and how he wanted just one day to get away from everything to spend some quality time with Milotic. Dawn apologizes for disturbing them, but Wallace says it's no big deal. Before he gets too far, Ash mentions that Dawn is going to be entering the Wallace Cup. Wallace then asks if Dawn would show off some of her combinations right in front of him! Dawn is hesitant at first, but Ash decides to have her battle him just for fun. Dawn agrees and everyone heads over to a smoother area for a contest battle.
Dawn is obviously using Piplup as she tries to calm her nerves. Ash calls on Buizel while Brock tells Wallace that Dawn was Buizel's original trainer and that she and Ash traded Pokemon that preferred the other trainer's goals and aspirations. The battle starts quickly as Piplup's Bubblebeam and Buizel's Sonicboom result in a stalemate. Ash has Buizel use Water Gun, but Dawn has Piplup use the spin dodge they've used many times before which catches Wallace's attention. Piplup then uses Peck which is defended well by Buizel who seems unphased by the attack. Ash then has Buizel use Aqua Jet as Wallace comments that the water brings out the best in Buizel. Dawn counters by having Piplup use Whirlpool and the 2 attacks result in yet another stalemate. Buizel and Piplup land and before another attack is called, Wallace asks them to stop for a bit of analysis. Ash and Dawn both agree that it would be a good idea to hear from Wallace about their strengths and weaknesses.
At the "debriefing" Wallace comments on how well Buizel moves around and asks Ash if he would consider entering the Wallace Cup with Buizel. After contemplating for a moment, Ash let's Buizel make the final decision. It seems to be up for it so Ash agrees to do it. Wallace then dissects Dawn's performance. He says that Dawn used her moves nearly flawlessly, but wanders if Dawn has played with her Pokemon lately and that perhaps she's trying too hard. Soon Jesilina(Jessie in disguise) along with James and Meowth(also in disguise) come up on the scene. Seeing as there are aspiring coordinators around, Wallace asks if everyone would like to stick around to watch he and Milotic put on an appeal performance. Nobody sees why they shouldn't and they all gather at lakeside.
Wallace has Milotic start with Safeguard and go straight into an Aqua Ring. Everyone is impressed at the combo of non-attacking moves and how graceful it looks. Wallace has Milotic use Twister next which breaks apart the Aqua Ring into a beautiful rain or something similar to it. Everyone is impressed by the performance as Wallace offers a few parting words before leaving. Back at the Pokemon Center, Ash and co. share thoughts on the day they had and they all ponder exactly what Wallace meant by "play with your Pokemon". Nurse Joy suddenly comes up and tells Ash that he has a phone call from Snowpoint City. Ash goes to take it as we cut to the Snowpoint City Pokemon Center and we see someone who looks very similar to May. Her voice is instantly recognizable as May's and the episode ends with a possible reunion on the horizon for Ash, Brock, and May.